nParticleShape
 
 
 
Enable

When on, the nParticle object is included in its Maya® Nucleus solver’s calculations. When off, the nParticle object behaves like a regular particle object and it is not included in its Maya Nucleus solver’s calculations.

Lifespan

Particle Size

Radius

Determines the overall radius of the nParticle object. The Radius setting provides the input value for the Radius Scale ramp.

Radius Scale

The Radius Scale ramp sets per-particle radius scale values which are applied to the Radius attribute to compute per-particle radius values. The vertical component represents the Radius Scale values from 0 (no radius) to 1 (equal to the Radius attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

If the Radius Scale Input is set to Off, the per-particle attributes are deleted. If it is set to any other value, the radius per-particle attributes are created if they don’t already exist.

Selected Position

Indicates the position of the selected value on the ramp (between 0 on the left to 1 on the right).

Selected Value

Indicates the per-particle attribute value on the ramp at the selected position.

Interpolation

Controls the way per-particle attribute values blend between each position on the ramp. The default setting is Linear.

None

The curve is flat between points.

Linear

The per-particle attribute values are interpolated with a linear curve.

Smooth

The per-particle attribute values are interpolated along a bell curve, so that each value on the ramp dominates the region around it, then blends quickly to the next value.

Spline

The per-particle attribute values are interpolated with a spline curve, taking neighboring indices into account for greater smoothness.

Radius Scale Input

Specifies which attribute is used to map the Radius Scale ramp values.

Off

When off, the per-particle attributes are deleted. If you want to use an expression with the per-particle attribute, you need to manually add them again. See Set attributes on a per particle basis.

Age

The per-particle attribute values are determined by the nParticle’s age, which is based on the particle Lifespan mode. See Lifespan Attributes.

Normalized Age

The per-particle attribute values are determined by the normalized age of the nParticle. To use Normalized Age, the nParticle object must have a defined lifespan. For example, the nParticle object’s Lifespan Mode attribute must be set to Constant or Random range. See Lifespan Mode.

When Normalized Age is used, The per-particle attribute values are mapped within the range of the nParticle object’s lifespan.

Speed

The per-particle attribute values are determined by nParticle speed.

Acceleration

The per-particle attribute values are determined by nParticle acceleration.

Particle ID

The per-particle attribute values are determined by the nParticle’s ID. Particle IDs are unique and generated at the beginning of the particle’s lifespan.

Randomizing ID

The per-particle attribute values are determined by a randomized nParticle ID.

Input Max

Sets the maximum value for the range used by the ramp.

Radius Scale Randomize

Sets a random multiplier for the per-particle attribute values.

Collisions

Collide

When on, the current nParticle object collides with passive objects, nCloth objects, and other nParticle objects that share the same Maya Nucleus solver. When off, the current nParticle object does not collide with passive objects, nCloth objects, or other nParticle objects that share the same Maya Nucleus solver.

Self Collide

When on, particles generated by the nParticle object collide with each other. When off, these particles do not collide with each other.

Collide Strength

Specifies the strength of collisions between nParticles and other Nucleus objects. At the default value of 1, nParticles fully collide with each other and with other Nucleus objects. Collide Strength values between 0 and 1 dampen the full collision, while 0 turns off nParticle collisions (which has the same as effect as turning off the object's Collide attribute). Setting Collide Strength to values greater than 1 slightly increases the force of collisions, while values less than 0 can create a weak repulsive force between objects.

You can set Collide Strength on a per-particle basis with a Collide Strength Scale ramp.

Collision Layer

Assigns the current nParticle object to a specific collision layer. Collision Layers determine how nParticle, nCloth, and passive objects that share the same Maya Nucleus solver interact.

nParticle objects on the same collision layer collide normally. However, when nParticle objects are on different layers, particles on lower value layers will have priority over particles on higher value layers. So an nParticle object on collision layer 0.0 will push an nCloth object or another nParticle object on collision layer 1.0, which in turn will push an nCloth object or another nParticle object on collision layer 2.0. This collision priority occurs in the range set by the Collision Layer Range attribute on the nucleus node.

NotenCloth and Passive objects in collision layers only collide with nParticle objects that are in the same collision layer, or in layers of higher value.

See Collision Layer in the nClothShape node description.

Collide Width Scale

Specifies a collision scale value for collisions between the current nParticle object and other nucleus objects.

Self Collide Width Scale

Specifies a self-collision scale value for the current nParticle object. Self Collide Width Scale allows you to scale the thickness of collisions that occur between particles emitted from the same nParticle object. Setting Self Collide Width Scale improves the smoothness of particle emission of self colliding particles, and speeds up the simulation. Self Collide Width Scale is 1.0 by default.

Solver Display

Specifies what Maya Nucleus solver information is displayed in the scene view for the current nParticle object. Solver Display can help you better diagnose and troubleshoot any problems you may be having with your nParticles.

Off

No Maya Nucleus solver information is displayed in the scene view.

Collision Thickness

When on, the collision volumes for the current nParticle object are displayed in the scene view. Collision Thickness helps you visualize the thickness of colliding nParticles and it is useful when tweaking nParticle collisions with other nParticle objects or nCloth and passive objects.

Self Collision Thickness

When on, the self-collision volumes for the current nParticle object are displayed in the scene view. Self Collision Thickness helps you visualize nParticle self-collision thickness and it is useful when tweaking nParticle self-collisions (collisions between particles emitted from the same nParticle object).

Display Color

Specifies the color of the collision volumes for the current nParticle object. Display Color is only visible when your scene view display mode is set to Shading > Smooth Shade Selected Items or Shading > Flat Shade Selected Items.

Bounce

Specifies the springiness or bounciness of the current nParticle object. Bounce determines the amount of the nParticle’s deflection or rebound on collision with itself, passive objects, nCloth or other nParticles objects that share the same Maya Nucleus solver.

The amount of Bounce an nParticle object should have is determined by the type of nParticle effect. For example, nParticles with a Bounce of 0.0 would not be bouncy (such as steel) and an nParticle with a Bounce of 0.9 would be very bouncy (such as rubber). Bounce is 0.0 by default.

NoteBounce values greater than 1.0 can cause instability and should be avoided.
Friction

Specifies the amount of friction for the current nParticle object. Friction determines how much nParticles resists relative motion on collision with itself, passive objects, nCloth, and other nParticle objects that share the same Maya Nucleus solver.

The amount of Friction an nParticle object should have is determined by the type of nParticle effect. The affect of Friction is influenced by the nParticle object’s Stickiness value. See Stickiness.

Stickiness

Stickiness specifies the tendency of nParticles to stick to other Nucleus objects when nCloth, nParticle, and passive objects collide.

Stickiness and Friction are similar attributes in that Stickiness is an adhesion force in the normal direction, while Friction is a force acting in the tangent direction. As with Friction, the Stickiness value used in a collision is the sum of the two colliding objects. So, for full sticking, the Friction and Stickiness on the colliding objects should be 1.0. Note that if Stickiness and Friction are both set to 2 on an object, this object will stick to other Nucleus objects that have Stickiness set to 0.

For particles from the same nParticle object to stick to each other, Self Collide must be turned on.

Max Self Collide Iterations

Specifies the maximum number of iterations per simulation step for the current nParticle object's dynamic self collisions. Max Self Collide Iterations clamps the number of iterations to prevent high level property values or a large number of steps from locking up the nParticle object.

Collision Ramps

Collide Strength Scale

The Collide Strength Scale ramp sets per-particle collide strength scale values. These scale values are applied to the Collide Strength attribute to compute per-particle collide strength. The vertical component represents the Collide Strength Scale values from 0 (no collide strength) to 1 (equal to the Collide Strength attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

If the Collide Strength Scale Input is set to Off, the per-particle attributes are deleted. If it is set to any other value, the collide strength per-particle attributes are created if they don’t already exist.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Collide Strength Scale Input

Specifies which attribute is used to map the Collide Strength Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Bounce Scale

The Bounce Scale ramp sets per-particle bounce scale values. These scale values are applied to the Bounce attribute to compute per-particle bounce. The vertical component represents the Bounce Scale values from 0 (no bounce) to 1 (equal to the Bounce attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

If the Bounce Scale Input is set to Off, the per-particle attributes are deleted. If it is set to any other value, the bounce per-particle attributes are created if they don’t already exist.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Bounce Scale Input

Specifies which attribute is used to map the Bounce Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Friction Scale

The Friction Scale ramp sets per-particle friction scale values. These scale values are applied to the Friction attribute to compute per-particle friction. The vertical component represents the Friction Scale values from 0 (no friction) to 1 (equal to the Friction attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

If the Friction Scale Input is set to Off, the per-particle attributes are deleted. If it is set to any other value, the friction per-particle attributes are created if they don’t already exist.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Friction Scale Input

Specifies which attribute is used to map the Friction Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Stickiness Scale

The Stickiness Scale ramp sets per-particle stickiness scale values. These scale values are applied to the Stickiness attribute to compute per-particle stickiness. The vertical component represents the Stickiness Scale values from 0 (no stickiness) to 1 (equal to the Stickiness attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

If the Stickiness Scale Input is set to Off, the per-particle attributes are deleted. If it is set to any other value, the stickiness per-particle attributes are created if they don’t already exist.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Stickiness Scale Input

Specifies which attribute is used to map the Stickiness Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Dynamic Properties

Forces In World
Ignore Solver Gravity

When on, solver Gravity is disabled for the current nParticle object.

Ignore Solver Wind

When on, solver Wind is disabled for the current nParticle object.

Dynamics Weight
Conserve
Drag

Specifies the amount of drag applied to the current nParticle object. Drag is the component of aerodynamic force parallel to the relative wind which causes resistance. Drag is 0.05 by default.

Damp

Specifies the amount the motion of the current nParticles are damped. Damping progressively diminishes the movement and oscillation of nParticles by dissipating energy.

Mass

Specifies the base mass of the current nParticle object. Mass determines the density or the weight of an nParticle object when its Maya Nucleus solver’s Gravity is greater than 0.0.

The Mass an nParticle should have is determined by the type of nParticle effect you want to achieve.

Mass affects behavior in collisions and behavior with Drag. nParticles with high Mass have greater influence on other nParticle or nCloth objects with low Mass, and they are less influenced by Drag.

Mass Scale

The Mass Scale ramp sets per-particle mass scale values which are applied to the Mass attribute to compute per-particle mass values. The vertical component represents the Mass Scale values from 0 (no mass) to 1 (equal to the Mass attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Mass Scale Input

Specifies which attribute is used to map the Mass Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max
Mass Scale Randomize

Sets a random multiplier for the per-particle attribute values.

Force Field Generation

Generates a force field that can push (positive fields) nCloth objects and other nParticle objects away from the current nParticles, and pull (negative fields) nCloth objects and other nParticle objects toward the current nParticles. A Point Force Field can only be exerted on Nucleus objects that are assigned to the same Nucleus solver as the nParticle object generating the Point Force Field.

See Force Field Generation.

Point Force Field

Sets the orientation of the Point Force Field.

Off

When turned off, the Point Force Field is not enabled.

World space

Point Force Field is set relative to world space.

Thickness Relative

Point Force Field is relative to the radius of individual nParticles. nParticles with higher Radius values generate stronger Point Force Fields relative to nParticles with low Radius values.

See Radius.

Point Field Magnitude

Sets the strength of the Point Force Field. Positive Point Field Magnitude values push nCloth objects and other nParticle objects away from the current nParticles. Negative Point Field Magnitude values pull nCloth objects and other nParticle objects toward the current nParticles.

Self Attract

Sets the strength of self attractive forces between the points (individual particles) of an nParticle object. Positive Self Attract values pull the points (individual particles) of an nParticle object together. Negative Self Attract values push the points (individual particles) away from each other.

Point Field Distance

Sets the distance (in field units) from the radius of the force generating nParticle that the Point Force Field is active. Outside the Point Field Distance, the Point Force Field does not affect nCloth objects and other nParticle objects.

Point Field Scale

Sets a Point Field Scale ramp that can be used to vary Point Field Magnitude along the Point Field Distance. See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

Selected Position

This value indicates the position of the Point Field Magnitude on the ramp. The left position on ramp represents Point Field Magnitude at the outside radius of the nParticles. The right position on the curve represents Point Field Magnitude at the edge of the Point Field Distance.

Selected Value

This value indicates Point Field Magnitude at the selected position.

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Point Field Scale Input

Specifies which attribute is used to map Point Field Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Point Field Dropoff

Sets a ramp that specifies how much the Point Field Magnitude drops off as you move away from the nParticle and toward the edge of the area defined by Point Field Distance. See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

Selected Position

This value indicates the amount of Point Field Dropoff on the ramp. The left position on ramp represents the amount Point Field Dropoff at the outside radius of the nParticles. The right position on the curve represents Point Field Dropoff at the edge of the Point Field Distance.

Selected Value

This value indicates the magnitude of the Point Force Field at the selected position.

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Rotation

Compute Rotation

When on, nParticles rotate on a per-particle basis after they collide or self-collide. Compute Rotation also creates Rotation PP and Angular Velocity PP per-particle attributes on the nParticleShape node.

You can use Rotation PP to rotate instanced geometry on a per-particle basis. Rotation PP and Angular Velocity PP can be used with an expression to add and control per-particle rotations.

Rotation Friction

Sets the amount of friction that is applied to particles during collision or self-collision. Increasing Rotation Friction increases the tendency of particles to rotate. When set to 0, particles do not rotate.

You can add Rotation Friction PP as a dynamic attribute and use it to control rotations in an expression.

Rotation Damp

Specifies the amount of damping applied to the nParticle's rotational velocity. Increasing Rotation Damp causes particle rotation to slow down after collision or self collision. When set to 0, no damping is applied to the rotation, causing the particles to rotate forever if no collisions or self collisions occur.

You can add Rotation Damp PP as a dynamic attribute and use is to control rotations in an expression.

Wind Field Generation

Air Push Distance

Specifies the distance over which the wind created by the motion of the current nParticle object affects nCloth objects or other nParticle objects in the same Nucleus system. The motion of the current nParticle object determines the direction of the wind.

When Air Push Distance is 0, no wind is generated by the motion of the current nParticles. When Air Push Distance is greater than 0, the wind created by the motion of the current nParticle object affects nCloth or other nParticle objects in the same Nucleus system. The higher the Air Push Distance, the greater the distance over which the wind created by the motion of the current nParticle object affects nCloth or other nParticle objects in the same Nucleus system.

Note
  • We recommend that you do not use Wind Shadow Distance and Air Push Distance together.
  • Air Push Distance is more processor-intensive than Wind Shadow Distance.
  • The effect of Air Push Distance is relative to the wind velocity, so a stationary object will slow down the wind within the push distance.
Air Push Vorticity

Specifies the amount of circulation or rotation in the flow of air being pushed by the current nParticle object, as well as the amount of curl in the flow of wind created by the motion of the current nParticle object. Air Push Vorticity changes the direction of the wind created by the motion of the current nParticle object.

Air Push Vorticity only affect’s your nParticles when Air Push Distance is greater than 0.

Wind Shadow Distance

Specifies the distance over which the current nParticle object blocks the dynamic wind of its Nucleus system from other nParticle, nCloth, and passive objects in its system.

When Wind Shadow Distance is 0, no wind is blocked by the current nParticle object. When Wind Shadow Distance is greater than 0, the dynamic wind of its Nucleus system is blocked by the current nParticle object. The higher the Wind Shadow Distance, the greater the distance for which the current nParticle object blocks the dynamic wind of its Nucleus system.

Wind Shadow Diffusion

Specifies the amount the dynamic wind curls around the current nParticle object as it blocks the dynamic wind of its Nucleus system.

Wind Self Shadow

When on, the current nParticle object blocks the dynamic wind of its Nucleus system from affecting itself.

Liquid Simulation

Enable Liquid Simulation

When on, Liquid Simulation properties are added to the nParticle object. See Liquid Simulations.

Incompressibility

Specifies the amount liquid nParticles resist compression. For water-like liquids, use low values. Increasing Substeps on the nucleus node magnifies the affect of Incompressibility.

Rest Density

Sets the arrangement of nParticles in the liquid when the nParticle object is at rest. A Rest Density of 2 specifies that, when the nParticles are settled, on average, there would be 2 nParticles overlapping at any point. A value of 2.0 provides good results for most liquids.

Liquid Radius Scale

Specifies the amount of overlap of nParticles based on nParticle Radius. Lower values increase overlap between nParticles. A value 0.5 provides good results for most liquids.

Viscosity

Viscosity represents the resistance of the liquid to flow, or how thick, and non-liquid the material is. When this value is high, the liquid flows like tar. When this value is small, the liquid flows more like water. For example, a value of 0.01 produces water-like liquids. For more viscous liquids, use a value of 0.1.

Increasing Substeps on the nucleus node magnifies the affect of Viscosity.

Viscosity Scale

The Viscosity Scale ramp sets per-particle viscosity scale values. These scale values are applied to the Viscosity attribute to compute per-particle viscosity. The vertical component represents the Viscosity Scale values from 0 (no viscosity) to 1 (equal to the Viscosity attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Viscosity Scale Input

Specifies which attribute is used to map the Viscosity Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max
Surface Tension

Specifies the amount of surface tension applied to liquid nParticles. Surface Tension is an attractive force that creates contracting and expanding behavior on the surface of a liquid nParticle object as it moves. The effects of Surface Tension are intended to add realistic surface tension to your nParticle liquid simulations.

The higher the Surface Tension values, the greater tendency nParticles have to attract one another, which causes the overall surface area of the nParticle object to become smaller and more uniformly covered.

Surface Tension affects the behavior of all nParticles belonging to the object, not just those that are visible at the surface of the liquid effect.

Surface Tension Scale

The Surface Tension Scale ramp sets per-particle scale values. These scale values are applied to the Surface Tension attribute to compute per-particle surface tension. The vertical component represents the Surface Tension values from 0 (no surface tension) to 1 (equal to the Surface Tension attribute value). See nParticle internal ramps and per-particle attributes and Set nParticle internal ramps.

Selected Position
Selected Value

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Surface Tension Scale Input

Specifies which attribute is used to map the Surface Tension Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Output Mesh

Output Mesh attributes allow you to control the size, smoothness, and dynamic characteristics of Blobby Surface nParticle objects when they are converted to polygon meshes. To see the effects of Output Mesh settings, you must first convert your nParticle object to a polygon mesh by selecting Modify > Convert > nParticles to Polygons. nParticles must be either created or emitted into the scene to be converted to polygons. nParticles emitted after the conversion will continue to add to the size and overall appearance of the nParticle output mesh. Output Mesh attributes are applicable all Particle Render Type nParticles. However, the nParticle output mesh always creates an iso-surface, which is based on nParticle Radius and Threshold.

NoteAfter your nParticle object is converted to a polygon object, Maya no longer displays the particles in the scene view. This reduces simulation time and makes it easier to see how your Output Mesh attribute adjustments affect the mesh. To make the nParticle object visible in the sene, in the Object Display section of the nParticleShape node Attribute Editor, turn off Intermediate Object.
Threshold

Determines the smoothness of the surface created by overlapping Blobby Surface nParticles. Threshold is based on the overall density of overlapping nParticles. Each nParticle has a density of 1 at its center, which then falls off to a value of 0 at the nParticle's edge.

Blobby Radius Scale

Specifies the amount nParticle Radius is scaled to create an appropriately smooth surface on Blobby Surface nParticles. Increasing Blobby Scale Radius does not affect nParticle Radius, meaning that nParticles can overlap due to Blobby Scale Radius without affecting their dynamic behavior. Increasing Blobby Scale Radius and Threshold together create smooth surfaces on nParticle output meshes.

Motion Streak

Motion Streak elongates individual nParticles based on the direction of nParticle motion, as well as the distance the nParticle travels in one time step. When Motion Streak is 0, nParticles are round. When Motion Streak is 1, nParticles are elongated to a length that is equal to the distance travelled in one time step. Motion Streak applies only to nParticles converted to nParticle output meshes. Motion Streak is useful for creating a motion blur type of effect, and for shaping the flow of Liquid Simulation effects.

Mesh Triangle Size

Determines the size of the triangles used to create the nParticle output mesh. Small Mesh Triangle Size produces high resolution output meshes with smoother surfaces. Small triangles take more computing resources and time to simulate. Mesh Triangle Size can be affected if the particle system bounds are very large relative to the set Mesh Triangle Size. See Max Triangle Resolution.

Max Triangle Resolution

Specifies the grid size that is used to create the output mesh. Max Triangle Resolution clamps the resolution of the voxel grid used in generating the nParticle output mesh's triangles. If the grid size required to create an nParticle mesh exceed the Max Triangle Resolution value, the output Mesh Triangle Size automatically increases to compensate for increasing size of the mesh.

Mesh Method

Specifies the type of polygon mesh used to generate the nParticle output mesh iso-surface. By default, Mesh Method is set to Triangle Mesh.

Triangle Mesh

Converts nParticles to a cube polygon mesh using the marching cubes method.

Tetrahedra

Converts nParticles to a triangle polygon mesh using the marching tetrahedra method.

Acutete Trahedra

Converts nParticles to a triangle polygon mesh using the marching tetrahedra method, and produces a slightly higher resolution mesh than the Tetrahedra Mesh Method.

Quad Mesh

Converts nParticles to a quad polygon mesh.

Mesh Smoothing Iterations

Specifies the amount of smoothing applied to the nParticle output mesh. Smooth iterations increase the lengths of the triangle edges, making the topology more uniform, generating a smoother iso-surface. The smoothness of your output mesh increases with increased Mesh Smoothing Iterations values, however, calculation time also increases.

Color Per Vertex

When on, color per-vertex data is generated when you convert an nParticle object to an output mesh. Color per-vertex data is derived from the nParticle object's per-particle color values. The data is color set data and can be applied to the nParticle output mesh like other color set data.

Opacity Per Vertex

When on, opacity per-vertex data is generated when you convert an nParticle object to an output mesh. Opacity per-vertex data is derived from the nParticle object's per-particle opacity values. The data is color set data and can be applied to the nParticle output mesh like other color set data.

Incandescence Per Vertex

When on, incandescence per-vertex data is generated when you convert an nParticle object to an output mesh. Incandescence per-vertex data is derived from the nParticle object's per-particle incandescence values. The data is color set data and can be applied to the nParticle output mesh like other color set data.

Velocity Per Vertex

When on, velocity per-vertex data is generated when you convert an nParticle object to an output mesh. Velocity per vertex is derived from the internal mapping of nParticle velocity values to R, G, and B color values. You can use velocity per-vertex data to create motion blur when the mesh is rendered using mental ray for Maya renderer.

Velocity per-vertex data is passed to the output mesh through the polySurfaceShape node's color set named Motion Vector Color Set. By default this color set uses the velocityPV data generated from the nParticle object.

Uvw Per Vertex

When on, UVW texture coordinates are generated when you convert an nParticle object to a polygon mesh. The texture coordinates let you map a texture to the surface of your output mesh. See nParticle output meshes.

You may need modify the meshes' UVs to get the desired placement of the texture on the mesh. You can view and edit UVs using the UV Texture Editor. For more information about UVs, see Introduction to UV mapping and UV Texture Editor overview in the Modeling guide.

Use Gradient Normals

When on, user normals are created for the output mesh. The normals are based on the direction of the opacity gradient within the particle density. This can improve the appearance and smoothness of the nParticle output mesh, particularly in areas of the mesh that have thin triangles. This setting only affects the output nParticle mesh and not volume nParticle renders.

Caching

Specifies the simulation data that will be saved to a server or local hard drive when the current nParticle object is nCached.

Cacheable Attributes

Position

Caches Particle ID, Age, position, and rotationPP.

Position and Velocity

Caches Particle ID, Age, position, rotationPP, velocity, angularVelocityPP, and LifespanPP).

Dynamics and Rendering

Caches the following nParticle attribute data: Mass, radiusPP, opacityPP, rgbPP, incandescencePP, spriteNumPP, spriteScaleXPP, and spriteScaleYPP.

All

Caches the following nParticle attribute data: Particle ID, Age, position, rotationPP, velocity, angularVelocityPP, LifespanPP, Mass, radiusPP, opacityPP, rgbPP, incandescencePP, spriteNumPP, spriteScaleXPP, and spriteScaleYPP.

Memory Cache

When turned on, the motion your nParticle object is saved to memory (not to disk). If you cache data in memory for emitted nParticles, and then later change the rate or another attribute of the emitter or emitted nParticles, you must disable the cache to see the effect of the attribute change.

Emission Attributes

Max Count
Level Of Detail
Inherit Factor
Emission In World
Die On Emission Volume Exit
Emission Overlap Pruning

Removes newly emitted nParticles before they appear in the simulation based how much they will overlap with existing nParticles. This value scales the collision radius used to determine overlap. A value of 1.0 it guarantees no self collisions with other particles on emission.

Emission Random Stream Seeds

emitter

Shading

Particle Render Type
Depth Sort
Threshold

Determines the smoothness of the surface created by overlapping Blobby Surface nParticles. Threshold is based on the overall density of overlapping nParticles. Each nParticle has a density of 1 at its center, which then falls off to a value of 0 at the nParticle's edge.

Opacity

Sets the overall nParticle opacity.

Opacity Scale

The Opacity Scale ramp sets per-particle opacity scale values which are applied to the Opacity attribute to compute per-particle opacity values. The vertical component represents the Opacity Scale values from 0 (no opacity) to 1 (equal to the Opacity attribute value). nParticle internal ramps and per-particle attributes.

Selected Position

This value indicates the position of the selected opacity on the ramp (between 0 on the left to 1 on the right).

Selected Value

This value indicates per-particle opacity on the ramp at the selected position.

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Opacity Scale Input

Specifies which attribute is used to map Opacity Scale ramp values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max
Opacity Scale Randomize

Sets a random value multiplier for the per-particle opacity scale values.

Color

The Color ramp defines a range of color values used for nParticle. The particular colors selected from this range correspond with the values for the selected Color Input. Color Input values of 0 map to the color at the left of the ramp, Color Input values of 1 map to the color at the right of the ramp, and values between 0 and 1 map to the color corresponding with the position on the ramp. nParticle internal ramps and per-particle attributes.

Selected Position

This value indicates the position of the selected color on the ramp (between 0 on the left to 1 on the right).

Selected Color

Indicates the color on the ramp at the selected position. To change the color, click the Selected Color box, and then select a new color from Color Chooser.

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Color Input

Specifies which attribute is used to map the ramp's color values.

Constant

Per-particle color is set to a single color value determined by the currently selected ramp position.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Sets a maximum multiplier for the range of RGB color values used by the Color ramp.

Color Randomize

Sets a random value multiplier for the per-particle color values.

Incandescence

Incandescence controls the amount and color of light emitted from the nParticles due to self illumination. The particular colors selected from this range correspond with the values for the selected Incandescence Input. Incandescent emission is not affected by illumination or shadowing. If the Incandescence Input is set to Off, the per-particle attributes are deleted. If it is set to any other value, the incandescence per-particle attributes are created if they don't already exist. nParticle internal ramps and per-particle attributes.

Selected Position

This value indicates the position of the selected color on the ramp (between 0 on the left to 1 on the right).

Selected Color

Indicates the color on the ramp at the selected position. To change the color, click the Selected Color box, and then select a new color from Color Chooser.

Interpolation

See Interpolation.

None

See None.

Linear

See Linear.

Smooth

See Smooth.

Spline

See Spline.

Incandescence Input

Specifies which attribute is used to map the ramp's color values.

Off

See Off.

Age

See Age.

Normalized Age
Speed

See Speed.

Acceleration
Particle ID
Randomizing ID
Input Max

Sets a maximum multiplier for the range of RGB color values used by the Incandescence ramp.

Incandescence Randomize

Sets a random value multiplier for the per-particle incandescence values.

Per Particle Attributes

See Set attributes on a per particle basis and Per particle and per object attributes.

Details on particle expressions can be found in the MEL and Expressions book.

Add Dynamic Attributes

See Add custom attributes.

Goal Weights and Objects

See Goal Weights and Objects.

Instancer (Geometry Replacement)

See Instancer (Geometry Replacement).

Render Attributes

See Render Attributes.

Render Stats

See Render Stats.

mental ray

See mental ray in the Rendering guide for more information.